Safety device for stamping presses



Patented Dec. 31, 1946 UNITED STATES PATENT OFFICE SAFETY DEVICE FORSTAMPING PRESSES Robert L. Aulenback, Shrewsbury, Mass. Application May15, 1944, Serial No. 535,774

1 Claim. 1

The invention relates to a metal stamping press or punch attachment, andmore particularly to a safety device for metal presses or punches.

The primary object of the invention is the provision of a, device ofthis character, wherein the hands of an operator will be excluded fromthe path of movement of the stamping press or punch tool as well as thestripper of such machine, thereby eliminating injury to such operatorduring the operation of the same.

Another object of the invention is the provision of a device of thischaracter, wherein it is adjustable to regulate the relationship betweenit and the press or stamping machine or the like, the device being inthe nature of a guard which automatically works concurrently with theoperation of the machine with which it is associated, and assuresagainst injury to an operator during the working of the said machine.

A further object of the invention is the provision of a device of thischaracter, wherein the same not only acts as a guard but it will pushthe arms or hands of an operator out of the path of the moving parts ofthe machine, so that any injury to the arms or hands is avoided, whilethe machine is in operation.

A still further object of the invention is the provision of a device ofthis character, which is simple in construction, thoroughly reliable andefficient in operation, strong, durable, readily and easily applied tothe machine, conveniently adjusted to the working conditions of suchmachine, automatic in its operation, and inexpensive to manufacture andinstall.

With these and other objects in view, the in vention consists in thefeatures of construction, combination and arrangement of parts as willbe hereinafter more fully described, illustrated in the accompanyingdrawings, which show the preferred embodiment of the invention, andhereinafter pointed out in the claims hereunto appended.

In the accompanying drawings:

Figure 1 is a front elevation of a punching machine showing the deviceconstructed in accordance with the invention applied thereto.

Figure 2 is a view similar to Figure 1 showing the device in a changedposition.

Figure 3 is a view similar to Figure 1 showing the device in a furthershiftedposition or opened.

Figure 4 is a side view thereof.

Figure 5 is a perspective view of one of the hanger brackets of thedevice detached.

Figure 6 is a sectional view taken on the line 66 of Figure 1 looking inthe direction of the arrows.

Figure 7 is a sectional view on the line 'l'l of Figure 1 looking in thedirection of the arrows.

Similar reference characters indicate corresponding parts throughout theseveral views in the drawings.

Referring to the drawings in detail, A designates generally andfragmentarily a standard type of a metal stamping machine, having asusual a bolster plate It), a die bed H, a plunger l2 co-aoting with thelatter, a punch l3 and a stripper plate M, the said punch and thestripper plate being co-related to each other in the conventionalmanner. The plunger reciprocates between spaced vertical gibs l5therefor and is power driven, as is common practice.

constituting the present invention is an adjustable safety device forattachment to the machine A, and this device comprises a, pair ofsubstantially L-shaped brackets or angle hangers It, each havingelongated slots I1 and I3, respectively, in its arms which are atsubstantially right angles to each other. These brackets or hangers I6are adjustably mounted on the gibs 15 by fasteners [9, which areaccommodated in the slots I8 and engaged in the gibs so that the slotsI! are forwardly of the said gibs 15 to be disposed transversely thereofin the same plane with one another.

Adjustably fitting the slots H are pivot bolts 20 for depending swinginglinks 2|, which are extended downwardly and are of uniform length withrespect to each other, the brackets or hangers being elevated relativeto the stripper plate Hi, and such links 2| are at opposite sides of thepath of movement of the plunger l2.

The links 2| at their lower ends are connected by pivots 22 to openingand closing guard arms, each including the upper and lower sections 23and 24, respectively. The upper sections 23 of these guard arms have thebent inwardly converging upper ends 25, which are pivoted at 26 to theplunger l2 outwardly spaced an equi-distance from the longitudinalvertical center thereof at the front face of such plunger. The sections2d are adjustably joined to the sections 23 by coupling sleeves 21carrying set screws 28, the sections 23 and 24 at their meeting endsbeing telescoped in the said sleeves. These sections 24 are formed withinwardly directed elbow lower ends 29 to have an underslung relationshipto the stripper plate M in the closing movements of the said arms, whilethe extreme free ends of such sections 24 are provided with outwardlycurled terminals or tips 30. The links 21 are pivoted to the sections 24at the outermost crotches of the elbow ends 29 bent therefrom.

In the working of the device when the punch l3 lowers by the descendingof the plunger l2, the guard arms which prior thereto are in full closedposition with relation to the stripper plate M, the elbow ends 29 beingunderslung thereto, open outwardly in a lateral direction, as is shownin Figure 3 of the drawings, thereby pushing the hands or arms of anoperator away from the path of the punch and out of danger of injuryfrom being caught between the punch and stripper plate while the machineis in operation. When the punch 13 is raised the device is in theposition shown in Figure 1 of the drawings, then when this punch beginsto lower the device gradually changes its position therefrom and itsarms open, the first opening step thereof being shown in Figure 2 of thedrawings.

By adjusting the sections 23 and 24 .of the guard arms of the device,they can be lengthened or shortened as may be required for the properworking of the said device and its fitting to the stamping machine orpress. Under this adjustment, the links 2| are regulated with relationto the brackets or hangers, as will be obvious.

From the foregoing, it is thought that the construction and manner ofoperation of the safety device will be clearly understood, and thereforea more extended explanation has been omitted for the sake of brevity.

What is claimed is:

A safety device of the kind described, comprising a pair of sectionalguard arms having pivotal connection with a movable part of a presscarrying a stamping tool for opening and closing movements with respectto the latter, means for adjustably connecting the sections of the armstogether for lengthening and shortening the same, hangers adjustablyconnected to a fixed part of the press, adjacent to and outside of thearms, links adj ustably pivoted to the hangers and fixedly pivoted tothe arms and inwardly directed elbows at the lower ends of the arms forunderslung movement of a stripper plate of the press.

ROBERT L. AULENBACK.

